"A group of Clemson students is determining how to use shredded leaves to help increase the value of roller-crimped cover crops. . . . ""Roller-crimping involves attaching roller-crimpers to tractors, rolling over cover crops to flatten and damage them, leaving behind a thick mulch."http://newsstand.clemson.edu/mediarelations/clemson-students-study-using-leaves-to-improve-roller-crimped-cover-crops/